Ballistic experts are studying whether any were involved in Wednesday's shooting in Lobelville, about 50 miles southwest of Nashville.

DeVine said agents were looking into all leads to piece together possible motives for the shooting. But the analyses of the weapons found at the teen's house suggested the suspect did not use a gun seized at the armory.

The suspect gained access to the building and fired several shots, authorities said. One struck Sgt. 1st Class Michael W. Braden, 45. He died later at a hospital.